Method And Apparatus For Virtualizing Hardware Dongle Over A Wireless Connection

ABSTRACT

In a computer system configured to handle I/O signals received by the computer system from input devices and/or output signals output by the computer system, a virtual attachment module includes logic for selecting such that program code for coupling can alter the operating system&#39;s selection of I/O devices used for particular I/O device operations, coupling to a wireless I/O device at least for determining whether the wireless I/O device is available, and causing redirection of I/O signals destined to a default I/O device to be to the wireless I/O device, if the program code for coupling determines that the wireless I/O device is available. A virtual connection module could be used to intercept system messages indicating a wireless device is present and connected, determine whether the wireless device is present and/or connected, and determine which intercepted messages to forward, drop, delay or reformulate.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. Provisional PatentApplication No. 61/358,358 filed on Jun. 24, 2010, which is incorporatedby reference in its entirety for all purposes.

This application may be related to U.S. patent application Ser. No.11/376,753, filed Mar. 14, 2006 naming Katelijn Vleugels (hereinafter“Vleugels I”), which is incorporated by reference in its entirety forall purposes.

FIELD OF THE INVENTION

The present invention relates to hardware interfacing to operatingsystem controls in general and more particularly to interfaces wherein acomputer's operating system performs actions based on whether a hardwareinterface device has been inserted or appears to be present.

BACKGROUND OF THE INVENTION

Wireless communication among electronic devices has been increasing asthe benefits and conveniences of wireless communication become morepreferred. Many computers (laptops, desktops, smart phones, handhelddevices, etc.) are equipped with wireless capability. Many computers arealso equipped with hardware expansibility, such as Bluetooth™ interfacesand Universal Serial Bus (USB) interfaces usable to connect peripheralsand other hardware devices with the computer.

In a computer having plug-and-play (“PnP”) capabilities, a hostinterfaces to a PnP software driver that signals to the operating systemwhen devices are attached and detached from the computer, signals theidentity of the type of device and possibly the particular instance ofthat type of device and handles the loading and unloading of devicedrivers accordingly. Using this PnP functionality, a user can simplyplug in a device, known to the computer or previously unknown to thecomputer, and the PnP layer will load the appropriate drivers (or askthem) so that the operating system services can access the installeddevice.

As used herein, “dongle” refers to a device commonly used to addwireless connectivity to a personal computer or other computer embedded(CE) device, or additional functionality provided elsewhere. A CE devicecan be any kind of electronic appliance that has embedded computertechnology. Examples of CE devices include, but are not limited to,personal computers, notebooks, set top boxes, home entertainmentsystems, TVs, game consoles, music players, media servers, cellularphone and/or smart phones. A typical dongle might have a USB plus, rangein size from about thumbnail size to thumb size, and have an internal orexternal antenna for wireless communication. Typically, upon beingplugged into a USB socket of a computer, keyboard, set-top box or otherCE device that has a USB socket, the dongle connects to the USB bus ofthe CE device. This connection is then detected by a USB host of the CEdevice, which determines the device instance (which particular devicethat is) and/or device type, and may signal for loading of appropriatedrivers for that device type. When the dongle is plugged into a CEdevice, it can provide a wireless transceiver function. Dongles mightprovide connectivity for wireless peripherals such as wireless mice, keyboards, audio headphones or audio headsets, or the like. In the exampleof a wireless mouse, when the dongle is plugged in and the wirelessmouse turned on, the mouse communicated through the dongle and isrecognized by the computer. The operating system loads the necessarysoftware to allow the mouse to move the screen cursor and perform othermouse action. Specifically, the wireless mouse detects user movementsand button selections and conveys input signals to the donglecorresponding to those user actions. The dongle conveys the inputs tothe USB bus and the USB functionality of the CE device moves that datawithin the CE device to be available to applications and other elementsof the CE device.

In general, dongles can be used for may interfaces wherein attaching adongle results in the dongle connecting to the bus driver and triggeringthe computer's operating system to assume that a new device is pluggedin and in turn triggers the operating system to run some “connectingprocessing” routine, such as Microsoft® Windows™ operating system PnProutine, or a signal rerouting. In some operating system, such a Apple'sMAC OS X™, attaching a dongle might change some settings so that a newdevice is mounted.

The approach of signaling when the device is attached and detached makessense to users, since there is a physical act that precedes actionstaken by the operating system, such as the operating system presenting amessage “New storage media found” and searching for content followingthe user inserting a thumb drive having content thereon.

In the case where the dongle provides wireless connectivity to devices,the dongle may act as a network adapter or it may represent itself tothe USB host as the actual wireless device that can connect to it. Ifthe dongle is a network adapter, then the insertion of the dongle isdetected by the PnP subsystem and the driver for a network adapter isloaded. When a Bluetooth™ device connects to the dongle, then this issignaled as a separate device and the appropriate driver for theBluetooth™ device is loaded. However, if the dongle is intimately tiedto the wireless device that can connect to it, then the insertion of thedongle typically causes the driver for that specific wireless device tobe loaded. This behavior is often times desirable as wirelessconnections may fade in and out without interrupting a user's task (solong as the fade is not too long), and it could be disruptive to alertthe user each time there is a change of state. This is not an issue withwired devices

In general, where a device connects wirelessly to peripherals or otherdevices over short links often referred to as forming a “personal areanetwork” or “PAN,” the device may use an external interface unit that isplugged into or onto the device. For example, where the device is alaptop, the circuitry might be provided by a USB dongle that attaches toa USB port of the laptop. The USB dongle contains the radio circuitryneeded to communicate wirelessly over the short wireless links. TheBluetooth™ interface is one such standard interface. The Ozmo Devicesinterface is another such interface.

In some cases, it might be desirable to reduce the amount of hardware inuse and, in the above scenarios, the lack of a physical dongle providesundesirable results, such as the inability to tie operation of thedongle with the insertion of the dongle and to assume constantconnections when the dongle is inserted.

BRIEF SUMMARY OF THE INVENTION

In some embodiments of the present invention, a plug-and-play (“PnP”)driver is provided that detects the presence or absence of wirelessdevices over a wireless channel and reports this information, andpossibly other information about the device, to the PnP subsystem sothat the PnP subsystem can load or unload the appropriate driver forthose devices at the appropriate time. The PnP driver thus simulates aphysical dongle, but obtains its traffic into and out of the computerover a wireless channel via a wireless networking interface and signalsan operating system to simulate the attachment and detachment of avirtual dongle to cause the operating system to trigger actions thatwould correspond with the attachment and detachment of a physical donglecoupled to a port of the computer.

In some specific embodiments of the present invention, a PnP driverpresents the wireless device to the PnP subsystem in such a manner thatit is able to make use of existing USB function drivers. As an example,when a wireless peripheral device connects, the PnP driver creates aphysical device object to represent this to the PnP subsystem. Inresponse, the PnP subsystem loads the appropriate USB function driversto handle the wireless peripheral device. The USB function driver can beunaware that it is communicating to a peripheral device wirelesslyrather than over the USB bus and still operate properly. Once connected,data from the wireless peripheral device are presented as regular USBdata to the USB function driver.

In some embodiments of the present invention, a PnP driver stimulatesattachment and detachment of a physical dongle where the signalingprovided to the PnP subsystem can be independent, under at least onecondition, from an actual state of a physical device supported by thePnP driver or from the state of the wireless channel. This allows thePnP driver to maintain the correct functionality from the perspective ofthe PnP subsystem regardless of whether or not the wireless channel isoperable. For example, where the actual state of the channel is that itis operable, the PnP driver could signal that the simulated device wasattached or that the simulated device was detached, and where the actualstate of the channel is that it is not operable, the PnP driver couldsignal that the simulated device was attached or that the simulateddevice was detached. Also, the PnP driver can delay notifications andskip some notifications where the state of the channel changes andreverts to its original state. For example, where the channelmomentarily becomes inoperable by then returns to operability withinless than a threshold time, the PnP driver can skip notifications ofthose two events.

Other objects, features, and advantages of the present invention willbecome apparent upon consideration of the following detailed descriptionand the accompanying drawings, in which like reference designationsrepresent like features throughout the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating elements of a computer anddevices that communicate with the computer, according to aspects of theembodiments disclosed herein.

FIG. 2 is a block diagram of an example wireless personal area network(PAN) system.

FIG. 3 is a block diagram of software components that might comprisesoftware and/or logical constructs to interface applications.

FIG. 4 is a block diagram of classes and objects that might be used inan interface between a network and applications.

FIG. 5 is a system overview of a simple speaker application usingaspects described herein.

FIG. 6 is a block diagram of a typical USB stack on which the inventionmight be used.

FIG. 7 is a block diagram of a driver stack.

DESCRIPTION OF THE DOCUMENT

the present disclosure describes methods and apparatus for operating andusing virtual dongle drivers to replace functionality provided byhardware dongles that add functionality to a computer system.

In the general example, references to a computer system can bereferences to computing devices which are portable and/or mobilecomputing devices and/or communications devices with some computingcapability. Examples of computing devices include laptop computers,desktop computers, handheld computing devices, pagers, cellulartelephones, devices with embedded communications abilities and the like.Examples of peripheral devices include typical computer, telephone, etc.accessories where wireless connections are desired, but might alsoinclude less common devices, such as wearable devices that communicatewith other devices on a person or even communicate with other nearbydevices. For example, tow people could exchange information betweentheir wearable computers without wires, by transmission through the air,or using their bodies and/or clothing.

The computing devices may interface to IEEE 802.11 WLANS (Wireless LocalArea Networks), or other wireless networks to communicate with othernetwork nodes, including nodes accessible through wired connections tothe wireless network (typically via an access point). The computingdevices also may interface to PAN devices over a personal area network(PAN), such as wireless headsets, mice, keyboards, accessories,recorders, telephones and the like. A wide variety of PAN devices arecontemplated that are adapted for short-range wireless communications,typically bi-directional and typically low power so as to conserve a PANdevice's limited power source. Some PAN devices might be unidirectional,either receive-only or transmit-only, devices.

In many examples herein, the plug-and-play (“PnP”) functionality is USBPnP, but these examples might be expanded to non-USB PnP or analogoussystems upon reading this disclosure.

Examples of the concepts and disclosures provided above will now befurther explained with reference to the figures. In the figures, likeitems are referenced with a common reference number with parentheticalnumbers to indicate different instances of the same or similar objects.Where the number of instances is not important for understanding theinvention, the highest parenthetical number might be a letter, such asin “100(1), 100(2), . . . , 100(N).” Unless otherwise indicated, theactual number of items can differ without departing from the scope ofthis disclosure.

Specifically, FIG. 1 illustrates various devices that might operatetogether. As shown there, a laptop 102 has wireless capability tointerface with an access point 104, a cell phone 106, a mouse 108, aprinter 110 and a wireless headset 112. Each of these devices can be incommunication with laptop 102 using the wireless link, either asconventional 802.11 devices or using an overlay protocol such asdescribed in Vleugels I. Instead of a laptop, another CE device might beused. In FIG. 1, elements are shown with an antenna to indicate thatthey can communicate wirelessly, but it should be understood that anexternal antenna is not required. Other network components andadditional instances might also be present. Wired components andperipherals (not shown), might also be present.

As is typically the case, when a peripheral is introduced to a laptopvia a USB connection, a USB module might signal that connection to theoperating system of the laptop. One response of the operating system isthe invocation of a search for a suitable driver. Another response ofthe operating system is the re-routing of signals, such as might occurwhere the laptop has integrated speakers that are the sound outputdevices until a wired headset is plugged into the audio jack of thecomputer, of which point power and/or signals are removed from thespeakers. Because of these responses, it might be inconvenient to theuser if the responses are not triggered appropriately.

FIG. 2 illustrates an example of the internal details of the laptop (butthis could be for some other device instead) computer 200. As explainedherein, such devices might include laptops, desktop computers,terminals, home entertainment systems, music devices, mobile phones,game consoles, network extenders or the like, that have capabilities ofresponding automatically to the attachment and detachment of peripheralsand/or other electronic equipment or interfaces.

What is shown in FIG. 2 is one example. In this example, a computer 200is shown comprising a processor 202, and a disk drive 204 and a programcode memory 206 in program and software instruction storage 207, a wiredinput/output interface 208 for displays, keyboards and the like, aninternal clock 209, and a network I/O interface 210, each coupled to abus 212 for intercommunication. A USB Host interface 214 is alsoprovided that can provide a path between devices attached to a USBconnector 216 and processor 202 via bus 212.

Program and software instruction storage 207 might comprise program codememory 206 and disk drive 204. Program instructions for implementingcomputing, communication, etc. functions, as well as networkinterfacing, can be stored in a program code memory 206 and might beloaded in there from instructions stored on disk drive 204. Memory 220might be just a portion of a common memory that also has program codememory 206 as a portion. For example, both memories might be allocatedportions of RAM storage so that instructions and data used by programsare stored in one memory structure. With a general purpose,network-centric, signal processing-centric or other style of processor,functional modules that might be illustrated by blocks in a blockdiagram might be implemented entirely in software, embodied only in codestored in computer readable media. However, when executed as intended,the processor and the stored instructions perform the functions of thosemodules. For example, a device might be described as having a networkstack that performs certain functions, but the network stack might notbe represented in individual hardware elements. Computing andinstruction processing of a given set of instructions might useconventional processor execution, instruction loading and storage,possibly optimized for the particular device.

FIG. 3 illustrates a platform 300 as it might be present in a dual-netdevice, that represents software and/or logical constructs that togetheror can be thought of as logical elements available for processing datawithin the computing device. As such, they need not be implemented asseparate hardware components or distinct software components, so long astheir functionality is available as needed. Other variations arepossible, but in the layout shown, applications and operating systemservices (shown as block 302) are programmed to interface to variousstacks, such as an IP networking stack 310 (sometimes referred to as an“IP stack”), a peripheral stack 312 (USB, HID, audio, etc.), a non-IPstack 314 (for IEEE 1394 interfacing or other stack 316. For example, anapplication such as an HTTP browser might expect to communicate usingTCP/IP and thus that application would have been configured tocommunicate with the computing device's IP stack.

A convergence platform can be added between an IEEE 802.11x (x=a, b, g,n, etc.) stack 322 and the different drivers to enable multi-protocolsupport, expose and coordinate access to specific MAC service primitivesand coordinate the priority handling in Quality-of-Service (QoS)sensitive applications. This convergence platform can be a separatesoftware layer or can also be integrated within the IEEE 802.11x stack322.

For certain stacks, additional services may be required that might notbe supported inside the IEEE 802.11x stack 322. If that is the case,such overlay protocol services may reside either inside the convergencelayer 320 or in between the convergence layer 320 and the respectivestack. As an example, communication with peripherals may requireprotocol services in addition to the protocol services provided by theIEEE 802.11x stack 322 in order to meet the power and latencyrequirement typical of such applications. Such protocol services may bepart of the convergence layer 320, or may reside in between theconvergence layer 320 and the Peripheral Interconnect Stack 312. Ofcourse, as an alternative, the IEEE 802.11x stack 322 may have beenadapted to support such services.

Each of the stacks 310-216 is shown coupled to a convergence layer 320,which provides the necessary and/or optional conversions of data,protocol, timing, etc. so that each of the higher level stacks 310-316are interfaced to an 802.11x stack 322. 802.11x stack 322 can theninterface to the computing device's network card (or other networkcircuitry). In this manner, for example, IEEE 802.11x stack 322 mighthandle a browser's traffic that goes through IP stack 310 while alsohandling a mouse interface whose traffic goes through peripheral stack312. Not that with a single 802.11x stack, a single network interfacecan carry traffic for more than one higher-level stack. The singlenetwork interface needs to be tuned to deal with the differentrequirements of the different stacks, when different requirements exist.

An example of this is illustrated in FIG. 4 for a wireless PAN where amouse is connected over the wireless channel to the standard HID classdriver in a PC running on the Windows™ operating system (or otherapplicable Operating System (OS)). The driver or firmware residesbetween the IEEE 802.11x stack 406 and the standard HID class driver403. In a specific implementation, the driver or firmware can constitutean HID adapter driver 404 and an 802.11x peripheral bus driver 405.

Other variations of what is shown in FIG. 4 are possible. For example,the IEEE 802.11x peripheral service function might connect up to MOUHIDdriver 402 directly. In that case, HID adapter driver 404 is written asan HIDCLASS miniport driver. This HID adapter driver then layers underthe MOUHID 402 and MOUCLASS 401 drivers and allows mouse data to beinjected into the operating system.

Alternatively, HID adapter driver 404 may be a bus driver that creates arepresentation of the device on a software bus in such a way that USBfunction drivers that are available to the operating system, or can bemade available through operating system modifications, can be layeredabove it.

In specific embodiments, the IEEE 802.11x peripheral service functionand adapter driver may be combined in a single driver. Alternatively,two separate drivers may be used and an interface might be defined andused between both drivers.

The HID adapter driver 404 receives the IEEE 802.11x frames from theIEEE 802.11x peripheral service function that are intended for thehigher layer driver (e.g., MOUCLASS driver 401). Similarly, the HIDadapter driver 404 receives frames from the higher layer driver that areto be transmitted to a PER using the IEEE 802.11x circuitry. The HIDadapter driver 404 and IEEE 802.11x peripheral service function generateand decode the necessary packet header for running a specificapplication, like the HID protocol, over an IEEE 802.11x data channel.For example, it removes the IEEE 802.11x-specific MAC header andperforms the necessary manipulation to transform it in the correctformat to be passed on to the respective class driver.

Specific Implementation

Software herein might be used with WPAN that enables peripherals toconnect to a Wi-Fi-enabled host using the IEEE 802.11x protocol. Using aparticular protocol with data type IEEE 802.11x frames and with IEEE802.11x basic access procedures, a bi-directional data path is providedbetween a peripheral and the Wi-Fi-enabled host. One example of such andIEEE 802.11x protocol is the protocol defined by the Wi-Fi Certified™Wi-Fi Direct specification. Another example might be the IEEE 802.11xprotocol supported by the Win7™ SoftAP™ or Intel My WiFi™ technology.Other protocols are also possible. Software for such operations might bedivided into two components: host-side software and device-sidesoftware.

The host-side software might run on a Wi-Fi-enabled host that supportsIntel MyWiFi™ or Win7™ SoftAP™ functionality. The embedded softwaremight run within the peripheral device, such as a device based on aCAST™ RX8051™ embedded core. The host-side software is responsible formanaging the communications link to the peripheral device andinterfacing the WPAN to the USB device driver appropriate for the classof service. It presents the device to the PnP manger in such a mannerthat it is able to make use of existing or newly created USB functiondrivers.

A system overview of a simple speaker application 500 is shown in FIG.5. A very similar architecture can apply to HID or other peripheraldevices.

When the speaker 502 (or other accessory) is first purchased, it doesnot have a partner host. This state is known as “unpaired”. A process isperformed by the user to cause a secure relationship to be establishedbetween the accessory and a host computer 504. This is known as“pairing”. Once paired, a specific embodiment of specially configuredevice will always search for its partner host device and ignore otherdevices. Pairing can be based on the Wi-Fi Alliance (WFA)™ ProtectedSetup specification (WPS)™ or a variant thereof. Different pairingmechanisms, based on different protocols or technologies such as, forexample, the Near Field Communication (NFC) protocol, are also possible.

An example device, such as speaker 502, may include one or more codec510, a speaker (or applicable I/O elements for that particular device),flash memory 514, a WPAN radio 516, a memory 518 (RAM, etc.) and amicrocontroller 520 coupled to each element, if needed, for controllingdevice operation as directed by program instructions stored in flashmemory 514.

On the host side, a standard Wi-Fi network interface 530 can be used tosupport the WPAN driver 532. This may be present already for use withother WLAN applications. WPAN drivers connect WPAN driver 532 to a USBfunction driver 534. An example of WPAN drivers are the drivers providedby Ozmo, but drivers provided by other than Ozmo can be used in place ofthe Ozmo drives, if proper functionality is supported. Audio data fromUSB audio input 540 could be conveyed to speaker 504 over the WPANinterface.

When a peripheral device, such as speaker 502, connects to its partnerhost device, WPAN driver 532 created an object to represent the physicaldevice to the PnP subsystem. In response, the PnP subsystem loads theappropriate USB function drivers to handle the device. The USB functiondriver need not be aware that it is communicating to a peripheral devicewirelessly rather than over the USB bus. Once configured, the devicewill obtain sensor data and pass this to the host, where it will appearlike USB data to the USB function driver.

Note that while communication occurs between the device and the WPANdriver, normal WLAN traffic may continue on through the network stack toa LAN driver 536. To ensure high QoS for the peripheral application, theWLAN traffic and the WPAN can operate on the same radio channel unlessthe radio in the host has a very fast channel switching time.

Host Software Architecture

USB data is transferred using a USB emulation protocol 538(implementable in a software block as illustrated) that enables theperipheral to appear as a conventional USB device in all aspects exceptpossibly data rate and latency. This approach has at least two benefits,including allowing a standard USB function or class driver to be layeredover the WPAN host drivers, and that the firmware in the applicationpart of the peripheral will be very similar to the firmware for a USBdevice of the same type.

The approach need not emulate USB at the electrical level or USB framelevel, but rather it does provide (1) an implementation of the USBstandard control request, (2) an implementation of the USB modelcontaining the familiar concepts, such as configurations, interfaces andendpoints, and (3) an interface at the upper edge that is compatiblewith that expected by Windows™ USB class and function drivers, amongother benefits.

This might not provide a complete emulation of the USB stack, but onlyparts relevant to attached WPAN peripherals such as providing a pathfrom a USB audio input 540 through to the peripheral speaker,wirelessly.

FIG. 6 shows a architecture of the USB stack 600 on a Win7™ PC, as butone example.

At the bottom of the stack is a USB host adapter 602, which is ahardware component that generates that USB packets on the wire. Thereare various standard interfaces supported by the Win7™ for O/S hostadapters. A USB host adapter miniport driver 604 drives a specific typeof adapter and at the upper edge 605 provides a standard interface.

A USB port driver 606 and the USB hub driver 608 together providegeneric USB stack functionality. They do not need to understand anythingabout specific classes of device, but provide the standard USB concepts,such as interface and endpoint. However, USB hub driver 608 does querysome of the USB descriptors form the USB device and, in conjunction withthe PnP manager, it determines the correct higher level driver to load.

Technically, USB hub driver 608 is a bus driver within the Windows™Device Model (WDM) architecture and, as such, creates the physicaldevice objects for the devices that are detected on the USB bus. Theseare reported to the PnP manger, which loads the appropriate functiondriver over the top. This function driver may either be a driver for thespecific device (based on the vendor and device identifiers) or may be ageneric class driver that understands how to drive all devices of aspecific class.

Above a USB class or function driver 610, there may be drivers specificto a particular class of devices (not shown). For example, for a USBmouse, the standard class driver is hidusb.sys, which itself is aminiport driver within the architecture of the hidclass.sys driver.Above hidclass.sys are layered the mouhid.sys and mouclass.sys driversthat finally provide the mouse functionality to user mode applications.

FIG. 7 shows an example architecture 700 of a WPAN driver 702 and itsrelationship to 802.11 hardware and driver as might be implemented inhardware and/or software. A WPAN driver stack 704 provides theequivalent functionality of a standard USB stack, up to and includingthe USB hub driver.

A standard NDIS miniport WLAN driver 706 supporting SoftAP™ or IntelMyWiFi™ technology can interface to WPAN driver 702 using the AP virtualadapter 708 available under Win7™ operating system. Differentimplementations are also possible. As an example, WPAN driver 702 caninterface to an NDIS miniport driver that implements the Wi-FiCertified™ Wi-Fi Direct specification.

WPAN driver 702 serves as an NDIS protocol driver and as a bus driver.

WPAN driver 702 can be an NDIS protocol driver layered on top of theSoftAP™ or MyWiFi™ AP Virtual Adaptor 708 and can identify frames usingthe Ethertype. This driver can implement a WPAN protocol and provideencapsulation services for a USB emulation protocol. Differentimplementations are also possible. As an example, the encapsulationservices of WPAN driver 702 can make use of the Internet Protocol (IP)

At the upper edge, the WPAN protocol driver provides an interface thatcan be the same as that provided by the standard USB hub driver. Thismeans that standard class and function drivers 710 can be layered overthe top of this driver.

The WPAN driver can also provide an IOCTL interface for user modeapplication and support a Windows™ Management and Instrumentation (WMI)interface. These interfaces enable interaction with the user through aGUI application.

The WPAN driver can act as a bus driver within the WDM architecture. Assuch, it creates physical device objects for peripheral in the WPAN.

The sequence of requests made to the WPAN bus driver by a functiondriver can vary. However, there are certain requests that are almostcertain to occur. Typically, the function driver will request the deviceand configuration descriptors for the device. The WPAN bus driver routesthis request to the WPAN protocol driver, which has already cached thesefrom earlier so can return them directly. The function driver willselect a configuration which will be routed through the WPAN protocoldriver to the peripheral. At this point, the WPAN bus driver will createobjects for the various interfaces supported in the configuration andalso the endpoints for the default alternatives for the interfaces.

Under USB data transmission and reception, requests are made on aparticular endpoint. The endpoint objects provide the queuing of USBRequest Blocks (URBs) which function drivers use to make requests to theWPAN bus driver.

Once the peripheral is configured, the majority of the requests from thefunction driver will be for transfers on a particular endpoint. The URBsfor these transfers are queued in the appropriate endpoint object. ForOUT transfers, the data is forwarded to the WPAN driver fortransmission. For IN transfers, the URB is queued in the endpointawaiting the reception of data from the peripheral. When such data isreceived by the WPAN bus driver, it puts the data in the URB andcompletes the URB.

Virtual Dongle Operations

Using the hardware described above as an example, various operations ofthe virtual dongle will now be described. As explained, the virtualdongle can be implemented entirely in software to emulate the physicaldongle (and therefore replace the need for it) such that the operatingsystem behaves as if a physical dongle is present and being attached anddetached. Thus, instead of requiring an operating system-USBdriver-dongle-peripheral path, the same functions can be performed by awireless network interface while still providing the same userexperience as wired devices. In some cases, there is a physical dongle,but the virtual dongle software will alter the signaling to theoperating system from the physical dongle to improve the userexperience.

The “virtual dongle” software sits beside the computer's operatingsystem and its I/O drivers, such as it USB function drivers. The I/Odrivers sit between I/O devices and the operating system as a pathbetween the I/O devices and elements of the operating system that expectinputs from those I/O devices and/or expect to be able to send outputsto those I/O Devices. For example, I/O drivers might include a keyboardinput driver that receives input from a keyboard plugged into thecomputer and feeds those inputs to the operating system, which in turnmight provide the inputs as key presses to an application program. TheI/O drivers also might include a mouse input driver that receives inputfrom a mouse plugged into the computer and feed those inputs to theoperating system, which in turn might provide the inputs as mouse clicksand movements to an application program. The I/O drivers also mightinclude a sound output driver that receives sound outputs from theoperating system (which might have gotten them from a game applicationprogram that seeks to output sounds) and feeds those outputs to a soundcard that, if it is connected to speaker, causes sounds to be made.

When some types of I/O devices are inserted into connectors of thecomputer, the operating system, possibly in conjunction with the PnPsubsystem, may inform a higher level software stack specific to thatdevice class which may decide to reroute I/O from the default device tothe plugged-in device, such that the default device does not handle theI/O and the plugged-in device does. When the operating system detectsthe disconnection of the plugged-in device, it reverts to using thedefault device. An example of this is a computer with built-in speakersthat play the sounds output by applications, but when a headset isplugged into the headset jack, only the headset outputs the sound.

In some conventions/systems, where the insertion of a physical dongle,rather than the connection of a wireless peripheral device itself,triggers the operating system to detect the presence of the wirelessperipheral device, the operating system has no knowledge of whether ornot the peripheral device itself is actually connected. As a result, thererouting of the I/O signal to the default or to another plugged-indevice upon disconnection of the wireless peripheral device cannothappen automatically. In fact, the user would have to unplug thephysical dongle to force the operating system to detect a disconnectionof the device and reroute the I/O back to a default or other plugged-indevice.

The virtual dongle described herein can detect whether a wireless deviceis present and connected and, if the device is present and connected,invoke an interaction with the operating system to simulate theinsertion of a hardware device, thereby allowing the operating system toswitch the I/O stream from the default device to the wireless device(via the virtual dongle).

The signalling by the virtual dongle software can be done based onwhether the wireless device is truly available (powered on, withinrange, connected, etc.), or might not exactly match availability, suchas when constant and accurate availability signalling would result in anadverse user experience or would not allow maintenance of the correct ordesired functionality from the perspective of the PnP subsystem. Thus,the virtual dongle may provide a “virtual disconnect” feature, softwarein a computer system that sits beside the computer's operating systemand its I/O drivers as understood by the operating system need not bethe actual I/O state. The operating system has logic to route I/Oaccording to device state (e.g., stop looking for mouse input from amouse that just got unplugged) and logic to provide alerts on statechanges (e.g., alert the user with a visual message and/or an audioSignal when a headset is unplugged or gets plugged in). The operatingsystem also has logic that might require certain set-up operations tooccur when a device moves from a disconnected state to a connected state(such as initialization, matching, pairing, testing, handshaking, etc.).The operating system might also have logic that performs operations whena device moves from a connected state to a disconnected state (such asclearing data structures used for a connection, etc.).

With the virtual dongle, the “presented state” (what the operatingsystem thinks is the state of the device) can vary from the “actualstate.” The virtual disconnect software might do this by interceptinginternal device connect and disconnect messages and injecting virtualmessages. For example, in some case, the virtual disconnect softwarechooses not to alter the states. In other cases, the virtual disconnectsoftware might, for particular devices, maintain a presented state of“connected” even while the device is known to the virtual disconnectsoftware to actually be disconnected. The virtual disconnect softwaremight maintain variables and settings and buffers as needed tore-establish the connection, all while the operating system considersthe device to still be connected. In some implementations, thismaintenance of the presented state can be held indefinitely, held untilanother action takes place, or held for a specified time period. Thiswould be useful, for example, where a device that is known to loseconnections for short periods can appear, to the operating system, to becontinuously connected.

In some implementations, an actual physical dongle is present but thevirtual disconnect software is still used in order to improve the userexperience.

The case that is used at any particular time for any particular devicemight be set ahead of time by the user, computer manufacturer, softwareprogram, etc., and stored in a configuration data structure, or it mightbe settable by the user in real-time, such as by an options switch onthe computer, as part of the software or as part of the particulardevice.

In an example of a specific implementation, a novel physicalwireless-interface dongle (“WID”) has a USB connector and when it isinserted into a USB connector (usually a socket, but not required), theWID is sensed by the host USB hardware as a USB device. However, the WIDneed not always “present” itself to the USB hardware, but can delay thatpresentation. In other words, the WID need not present itself to the USBbus as a direct consequence of being plugged into the USB connector. Onereason for this delayed presentation is that the WID can be a genericinterface for a plurality of different devices and it delayspresentation until it finds out what device it is the interface for.

The WID might be able to have a connection to the USB bus that iscontrolled by software by making use of a hardware feature that iscommonly present in USB interface chips that allows connection to theUSB bus to be controlled by software.

Once a device has wirelessly connected to the WID and providedinformation about what kind of device it is, the WID can then presentitself to the USB bus as a USB device. At this point the WID connects tothe USB bus and thereafter repackages and relays to the device thecontents of the USB messages received and transmitted over the USB bus.A private protocol might be used between the dongle and the device, or astandardized protocol might be used where appropriate. Most of theinformation contained in the USB messages can also be contained in themessages of this private protocol, although possibly in a reformulatedmanner.

Some USB messages can be entirely handled by the WID without requiringassistance from the device. At any one instant, the WID represents asingle USB device, but over time the WID could represent differentdevices, even of different classes, without the physical WID having tobe removed. The WID can effect this feature by choosing when to connector disconnect from the USB bus depending on the wireless connection withthe device. This ability to serially multiplex multiple USB devicesprovides advantages over conventional dongles that are dedicated tosingle USB devices or, for example in the case of the USB Bluetooth™ orWiFi adapter, are dedicated to being network interfaces, appearing as anetwork card rather than as a specific device.

The virtual disconnect software (1) detects whether a wireless device ispresent and connected, (2) intercepts system messages related toconnections and disconnections and (3) includes logic to determine whichintercepted messages to forward, drop, delay or reformulate.

Using the virtual dongle, peripheral devices such as mice, keyboards andaudio devices can connect to a host device using a radio that is builtinto the host device, such as a WiFi radio, and to then be internallyconnected to the USB auto-configuration software of the operatingsystem. When a peripheral device is turned on and connects to a hostdevice that has said software component installed, the peripheral devicecan operate in the same way that a conventional wired USB peripheralwould operate when plugged into a USB socket.

Wireless communications to a host device are diverted internally to asoftware driver that is responsible to pass data and event notificationsbetween the operating system and the peripheral device. When theperipheral device first connects, the software driver notifies theoperating system about the connection. This notification is equivalentto that which occurs when a physical connector is inserted to a USBsocket. The operating system reacts by invoking its PnP subsystem toinvestigate the function of the new device and load appropriate handlingsoftware, and also possibly rerouting signals to or from a defaultdevice and use the wireless device instead.

When the wireless device disconnects, the software driver has control ofnotification to the operating system. It has three options:

1) Do not provide notification to the operating system with the resultthat the device is not removed from the USB PnP system.

2) Provide immediate notification to the operating system with theresult that the device will be removed from the USB PnP system. This maycause a “disconnect” alert Sound and will require the USB PnP system torun again when the peripheral device reconnects.

3) Defer notification to the operating system for a period of time incase the wireless peripheral reconnects. In this case, the operatingsystem will not be aware that the disconnection has occurred and willthus take no action with respect to the USB PnP system. After adisconnection, the software driver can wait for a period and, if noreconnection occurs, it can then inform the operating system about thedisconnection. This “virtual unplug” function can be a substitute for auser unplugging a dongle some time after disconnecting the peripheraldevice. This function might also be used with physical dongles.

There might be a fourth option, in some implementations, wherein thesoftware driver emulates some function of the peripheral device eventhough it is not plugged in. For example, the software driver couldsimulate the sending of HID reports where this was useful orappropriate.

The use of the software driver to stand between the wireless peripheraland the operating system can be used instead of a physical dongle usedin many of today's products. For example, if a wireless devicedisconnects from a physical dongle, the operating system is not notifieduntil the physical dongle is unplugged.

Option (1) above is similar to an approach implemented by physicaldongles today, but results in a suboptimal user experience for certainwireless peripherals, such as audio headphones. Furthermore, since thevirtual dongle, unlike a physical dongle, might not be easily unpluggedmanually by the operator to terminate an auto-configuration, thisfunctionality is replaced.

In option (2), auto-configuration might only occur when the wirelessperipheral connects and by the same token, if the device wirelesslydisconnects, the operating system considers that it has been“unplugged.” As a consequence, the alert sound may be made each time theperipheral connects and disconnects. This represents a significantproblem for some devices such as wireless mice, which connect anddisconnect frequently in order to save power.

Even for headphones, option 2 could pose problems if a disconnectionoccurs due to the peripheral device temporarily going out of range. Ifthe session is terminated immediately upon disconnect, this could resultin undesirable long reconnect times when the headphones are brought backinto range.

The issues associated with options 1 and 2 are overcome with option 3.When a wireless peripheral connects, it informs the virtual donglesoftware whether it wishes to be supported by the virtual unplugfunction and indicates a required delay value for the virtual dongle tomaintain a session after disconnection. Thus, the behaviour of theglobal dongle software and the virtual unplug function might be dictatedby the particular devices used. The values might instead be provided bystored data objects.

The virtual dongle software can provide a token (numeric value) toidentify a session. If the wireless peripheral disconnects, it may uponreconnection present the token to the virtual dongle software and, ifthe virtual dongle software still has the session available, it can bereconnected silently. If the session has expired, the wirelessperipheral can be informed that a new session is to be established. Thevirtual dongle software may autonomously (without handshake form theperipheral) decide to implement a delayed notification.

Applicability of Virtual Unplug Function to Physical Dongles

To overcome certain limitations of existing physical dongles, a similarapproach to options (2) and (3) above for the virtual dongle can beapplied in the case where a physical dongle is present. For example, thevirtual unplug function could be used with a physical dongle, using thesame delaying technique with respect to notifications to the operatingsystem. In a specific case, the “connect” notification is not provideduntil a wireless device communicates to the physical dongle (rather thanwhen the dongle is plugged in). Similarly, disconnect notifications canbe propagated instantaneously or be deferred for a period to allow thewireless peripheral to connect and disconnect without disturbing theoperator.

While the present invention has been described herein with reference toparticular embodiments thereof, a latitude of modification, variouschanges, and substitutions are intended in the present invention. Insome instances, features of the invention can be employed without acorresponding use of other features, without departing from the scope ofthe invention as set forth. Therefore, many modifications may be made toadapt a particular configuration or method disclose, without departingfrom the essential scope and spirit of the present invention. It isintended that the invention not be limited to the particular embodimentsdisclosed, but that the invention will include all embodiments andequivalents falling within the scope of the claim.

1. In a computer system configured to handle I/O signals, the I/Osignals comprising input signals received by the computer system frominput devices and/or output signals output by the computer system, thecomputer system including operating system code that includes logic forrouting I/O signals between the operating system code and a plurality ofI/O devices and logic for selecting among the plurality of I/O devicesbased on which of I/O devices appear to the operating system code to beattached to the computer system, a virtual attachment module comprising:program code for coupling to the logic for selecting such that theprogram code for coupling can alter the operating system's selection ofI/O devices used for particular I/O device operations; program code forcoupling to a wireless I/O device at least for determining whether thewireless I/O device is available; and program code for causingredirection of I/O signals destined to be between the logic for routingand a default I/O device to be between the logic for routing and thewireless I/O device, if the program code for coupling determines thatthe wireless I/O device is available.
 2. The virtual attachment moduleof claim 1, further comprising a plug-and-play (“PnP”) driver that takesactions based on events including a device being plugged into thecomputer system and a device being unplugged from the computer system,wherein the PnP driver has access to indications of which devices areplugged in received from object modules corresponding to devices.
 3. Thevirtual attachment module of claim 2, comprising device objectscorresponding to wireless peripheral devices, wherein the device objectsprovide at least proxies for state of connections with the wirelessperipheral devices that are presented to the PnP driver.
 4. The virtualattachment module of claim 2, wherein the PnP driver is a USB PnPdriver.
 5. The virtual attachment module of claim 2, wherein the virtualattachment module includes logic for intercepting internal deviceconnect and disconnect messages and injecting virtual messages.
 6. Thevirtual attachment module of claim 1, comprising: program code for aconvergence layer between an IEEE 802.11x stack and drivers for one ormore of the plurality of I/O devices, wherein the convergence layerprovides access to MAC layer primitives of the IEEE 802.11x stack; andprogram code for coordinating priority handling in Quality-of-Service(“QoS”) sensitive applications.
 7. The virtual attachment module ofclaim 6, wherein the IEEE 802.11x stack supports overlay protocolservices that are partially compatible with an IEEE 802.11x protocolwith modifications to meet a power or latency constraint.
 8. In acomputer system configured to handle devices that connect and disconnectfrom the computer system, a virtual connection module comprising:program code for intercepting system messages indicating a wirelessdevice is present and connected; program code for determining whetherthe wireless device is present and/or connected; and program code fordetermining which intercepted messages to forward, drop, delay orreformulate.
 9. In a computer system configured to handle I/O signalsreceived by the computer system from input devices and/or output signalsoutput by the computer system, a virtual attachment module, operablewithin the computer system, comprising: logic for selecting of I/Odevices used for particular I/O device operations, coupled to storagefor a data structure indicating which I/O devices are selected; logicfor modifying the data structure such that at least one I/O deviceoperation is modified such that inputs and/or outputs are with aperipheral over a wireless interface; and a virtual dongle interfacethat provides, to computer system elements, a presented state of an I/Odevice connection, including logic to obtain an actual state of aperipheral, logic to provide the presented state and logic to determineat least one situation wherein the presented state is different from theactual state of the peripheral.
 10. The virtual attachment module ofclaim 9, further comprising logic for causing redirection of I/O signalsdestined to a default I/O device to be to the peripheral, if the programcode for selecting determines that the peripheral is available.
 11. Thevirtual attachment module of claim 9, wherein the logic to determine atleast one situation includes logic to signal the presence of theperipheral to computer system elements during a period in which theperipheral is not present, but a timer has not expired.
 12. The virtualattachment module of claim 11, wherein the logic to signal the presenceof the peripheral includes logic to determine intercepted messages toforward, drop, delay and/or reformulate.
 13. The virtual attachmentmodule of claim 9, wherein the logic to determine at least one situationincludes a virtual connection module usable to intercept system messagesindicating a wireless device is present and connected, determine whetherthe wireless device is present and/or connected, and determine whichintercepted messages to forward, drop, delay and/or reformulate.
 14. Thevirtual attachment module of claim 9, wherein the peripheral is awireless peripheral operating over an 802.11x protocol connection and/ora wireless personal area network (“WPAN”) protocol connection.
 15. Thevirtual attachment module of claim 9, further comprising a physicaldongle, wherein the virtual attachment module includes logic to altersignaling to the operating system from the physical dongle.
 16. Thevirtual attachment module of claim 15, wherein the physical dongle is awireless interface dongle with a wireless antenna.
 17. The virtualattachment module of claim 9, further comprising storage for variablesand settings and buffers usable to re-establish a connection with aperipheral while maintaining the operating system in a state that treatsthe peripheral as still being connected, indefinitely, until anotheraction takes place, and/or for a specified time period.
 18. The virtualattachment module of claim 9, wherein the virtual attachment module isconfigured to control notification to the operating system of wirelessdevice connections and disconnections, including skipping device removalnotifications to the operating system, sending device removalnotifications to the operating system, and deferring device removalnotifications to the operating system.
 19. The virtual attachment moduleof claim 18, wherein the virtual attachment module is further configuredto issue notification to the operating system of wireless deviceconnections under predetermined conditions when a wireless device is notconnected.
 20. The virtual attachment module of claim 18, wherein theattachment module is further configured to provide a token to identify asession and use the provided token to determine if a prior session is tobe reconnected or if a new session is to be created. 21-24. (canceled)